Originally Posted by
noglider
You say a lighter bike (or rider) makes a smaller difference than we expect. I can accept that, but I can't accept that it makes no difference. As I said, it gives me a 2 or 3 mph advantage.
Any reasonably differences in bike weight won't be the primary culprit in a 13mph vs 15mph difference on flat ground. My road bikes vary over a 13 pound range in weights, and they all perform much closer to each other than that when riding steady on the flats. Is your fit/posture about the same on both bikes, and are you running the same tires set up in the same way?